The choice is yours – you choose how you would like to eat. So if you can manage to only eat 1200 calories on your non fast days then you can, however this would not be considered a 5:2 diet, it is more like an extreme 7 day a week calorie restrictions diet of only 1000 calories a day.
How? – I hear you ask. I have tried to break it down for you below, by showing it to you in a mathematical equation.
Suggested 5:2 Diet:
2000 (TDEE) x 5 days = 10,000
500 x 2 days = 1,000
Total calories for the week
10,000 + 1,000 = 11,000
Divide that by 7 days in the week
11,000 ÷ 7 = 1571/day
Now you substitute the 2000 (TDEE) with your own TDEE
(see how to calculate your TDEE here)
Mine is 1811, and I struggle to eat that amount usually I eat around 1600, plus on my fast days I never eat all the way up to 500 anymore. So once averaged out over 7 days I am on around 1200/day.
Now if you only have 1200 on non fast days
1200 (restricted) x 5 days = 6,000
500 x 2 days = 1,000
Total calories for the week
6,000 + 1000 = 7,000
Divide that by 7 days in the week
7,000 ÷ 7 = 1000 cals/day
While only averaging 1000 calories a day your body with not go into the “mythical starvation mode” but if you are eating too little for too long it can put a lot of stress on your body over long periods of time.
When your body is put under stress due too not enough food for an extended period it will respond by producing cortisol. Cortisol is a hormone that increases your bodies resistance to insulin, which in turn encourages your body to store fat, rather than use it for fuel. This is why intermittent fasting is great as it does not put your body under stress for an extended amount of time. It is shown that a little bit of stress over a couple of days of fasting is good, but extended stress can be counterproductive.
Another reason for not doing a low calorie diet is because eating to little can also cause your body to retain water due to the lack of protein in your blood. Your body can store water, sugar and fat, naturally. However it has no way of storing protein, so if you do not get enough protein then your body will start to consume it’s muscles as a source of protein. So this will effect the results you are hoping to see on the scales.
And lastly, if low cal diets were successful long term, then no one would be looking at doing 5:2 as an alternative to the other diets options out there where 7 day a week calorie restriction always usually ends in failure.
Remember it is not a race, you may think that if you eat less you will lose weight quicker, but it will not be sustainable long term, and your body will be much happier if you take your time.
5:2 is not just to lose weight, it is something that you want to do to live a healthier and longer life.
